ASTM A 53 Gr B / API 5L Gr B - Carbon steel or Mild Steel?

[CREERAAM]

Hai,


While reviewing the MTR's for the ASTM A 53 Gr B / API 5L Gr B Pipes MTC the Carbon percent is mentioned upto 0.30 % is allowed by the standard specified limits, So this pipes are fall under MILD STEEL category or Low CARBON STEEL category?


Any standard is given clear detail about chemical composition of mild steel and carbon steel?

In generally the carbon percent only decides the steel category right then why the ASTM standards are not clearly stating that steel category in some standards LIKE mild steel, Carbon steel

ASTM A 106 Gr B - Mild Steel ?

ASTM A 53 Gr B - Mild Steel ?

ASTM A 234 WPB - Mild Steel ?

REGARDS,

G.SRIRAM.

Dream,Dream,Dream Dream transforms in to thoughts.And thoughts result in action

 

[mrfailure]

I generally consider steels below 0.15% carbon to be low carbon, while 0.15 - 0.30 to be mild. Of course, specs often straddle these definitions.

 

I don't get bothered by any such distinction, but I have rarely encountered 'mild steel' in industry.
The distinction I am more interested in is weldable, less weldable and non-weldable.


"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[DGrayPPD]

I've seen varying ranges, but what I've see most often falls in line with mrfailure.

Low Carbon Steel - less than 0.20% Carbon (although I've seen this number be 0.15% as well, as mrfailure stated)
Mild Steel - 0.20%-0.50% Carbon
High Carbon Steel - over 0.50% Carbon

As far as why ASTM doesn't clearly state the category... ... Maybe they don't think it's necessary. Maybe they assume the people reading the specifications already know that information. Maybe they think it's outside the scope of the document. Maybe it was just never brought up during the meetings. I don't know that you'll get a definite answer on that question.

"The only limits in life are those which we impose upon ourselves."

 

[weldstan]

All of your posted ASTM grades could be considered low carbon steels or mild steels.

 

[mrfailure]

The only time I use the distinction between low and mild carbon steel is as a descriptor in reporting. As Ironic noted, weldability is of more concern and it is defined by specific chemistry, not just the carbon content. There are equations to help you determine weldability to determine if you need to preheat and post-weld heat treat.